Apparatus for evaporating impurities contaminating liquid gas, for example acetylene contaminating liquid oxygen



Dec. 25, 1962 J. H. DOLPHIN ETAL 3,069,863

APPARATUS FOR EVAPORATING IMPURITIES CONTAMINATING LIQUID GAS, FOR EXAMPLE ACETYLENE CONTAMINATING LIQUID OXYGEN Filed July 18, 1958 INVENTORS- JOHANNES HENDRIKUS DOLPHIN JOHANNES VAN DER STER AGEN Eindhoven, Netherlands, assignors to North American Philips Company, Inc., New York, N.Y., a corporation of Delaware Filed July 18, 1958, Ser. No. 749,448 Claims priority, application Netherlands Lluly 24, 1957 2 Claims. (Cl. 62-42) The present invention relates to apparatus for vaporizing impurities contaminating liquid gas, for example acetylene contaminating liquid oxygen, more especially but not exclusively for use in gas-separating systems, comprising a wall which is adapted to be heated and on which a liquid is evaporated.

Such apparatus are known per se.

According to one prior proposal acetylene-contaminated liquid oxygen is drawn off from a fractionating column and fed through an atomizer to a separateheater where the liquid is evaporated by hot, gaseous oxygen.

Any liquid residue is collected into a heated tray and evaporated.

According to another prior proposal oxygen drawn 05 from a fractionating column and, for example, containinated by acetylene is fed in small quantities against a heated, fiat bottom of a vaporizer where it is evaporated by boiling on the plate, above which provision is made of a fairly large space with a narrowed supply duct for the liquid.

The present invention has for its object to provide an apparatus of the aforesaid type, without using overpressure for dispersion or a large chamber for boiling on a heated plate, while precluding any accumulation of acetylene.

In accordance with the invention, the heatable wall comprises recesses and elevations so as to permit individual and permanently individual drops of the liquid to be evaporated in the recesses or to jump over from one recess to the others.

Experiments have shown that, for example an oxide layer, actually having recesses and elevations and acting as a semiconductor with regard to the transfer of heat constitutes a particularly suitable vaporization surface for the liquids entering into account. Acetylene, for example, evaporates completely.

In a practicable form of the invention, the surface of the heatable wall consists of one or more layers of metal gauze, for example copper gauze. Excellent results are obtained when connecting, for example, three layers of gauze offset through an angle of, say, 45 relative to one another, by sintering or soldering to a massive metal, for example copper, substratum.

The vaporization surface according to the invention preferably constitutes entirely or partially the outer surface of a body having an outer surface converging towards the highest point, for example a cone or a ball cap. When using a cone, its vertical angle may have a value of the order of 120.

Particular attention has to be paid to supplying the liquid to be evaporated to such a body.

For example, in an advantageous form of the invention,

the body near its highest point co-acts with a distributor adapted for supplying liquid and having an upwardly converging outer surface, for example a conical surface or that of a ball cap, and which further meets at or near its highest point with a liquid supply duct projecting downwardly and comprising overhanging parts, for example teeth, at its lower edge.

A distributor of this type is described in US. patent application Serial No. 745,192, filed June 27, 1958, now abandoned.

In the device according to the present invention, its use is particularly advantageous.

In a further practical form of the invention, the liquid supply, for example from the distributor referred to, is directed towards a body having a smooth surface and so shaped, for example as a cone, that any liquid supplied to it is accelerated in flowing off, the stream of drops flowing ofi being directed towards the surface of the heatable wall provided with recesses and elevations.

In order that the invention may be readily carried into effect, an example will now be described in detail with reference to the accompanying schematical drawing, which is a longitudinal section of one form.

Liquid oxygen, for example contaminated by acetylene, is passed through an aperture 1 of a mouth piece 2 in the direction of arrows p to a distributor 3 in the form of a cone provided with overhangs 4 at its lower edge 5.

This cone has a strong distributing effect without any overpressure. Drops accumulate from the projections 4 and fall on the smooth outer surface of a cone 6. The drops are accelerated along the surface of the cone is and jump over to the heated conical gauze surface 7. Its temperature amounts to C. to C.

The evaporating drops jump over from one mesh to the others. They flow together, thus avoiding accumulation of acetylene.

The vapours produced escape into chamber 9 and thence through pipes 55.

Such apparatus may, for example, be used at the bottom end of gas-fractionating columns.

What is claimed is:

1. An apparatus for evaporating impurities such as acetylene from liquid oxygen in a gas fractionating column comprising means for dispensing liquid oxygen, coneshaped wall forming an angle of and positioned beneath the outlet for said dispensing means, said liquid oxygen being adapted to flow over said cone-shaped wall, a chamber located adiacent to said cone-shaped Wall and in open communication therewith, an opening in said chamber to the atmosphere, means for heating said coneshaped Wall, the latter being constituted of a metal gauze whereby the Leydenfrost phenomenon occurs and all liquid thereon is evaporated and the acetylene gas therein is discharged to the atmosphere through the opening in said chamber, a smooth, cone-shaped element connecting opposite faces of said cone-shaped wall, and a conical distribution plate positioned on said cone-shaped element with its apex directly underneath the outlet of said dispensing means, the base of said conical distribution plate overhanging said cone-shaped element.

2. An apparatus for evaporating impurities such as acetylene from liquid oxygen in a fractionating column comprising means for dispensing liquid oxygen, a sloping wall beneath the outlet of said dispensing means and over which said liquid oxygen flows, a chamber located adjacent to said sloping Wall and in open communication therewith, an opening in the chamber to the atmosphere, means for heating said sloping W211, the latter being a metai gauze constituted of a metal oxide material whereby the Leydenfrost phenomenon occurs and all liquid thereon is evaporated and the acetylene gas therein is discharged to the atmosphere through tie opening in said chamber.

References Iited in the file of this patent UNITED STATES PATENTS White Mar. 17, 1903 Anderson Ian. 28, 1913 Hanson Nov. 18, 192.4 Magnus Mar. 15, 1932 Frank June 19, 1934 Pape Dec. 11, 1955.. 

2. AN APPARATUS FOR EVAPORATING IMPURITIES SUCH AS ACETYLENE FROM LIQUID OXYGEN IN A GAS FRACTIONATING COLUMN COMPRISING MEANS FOR DISPENSING LIQUID OXYGEN, A 